Thin film device and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9378981-B2
Application number	US-201514687459-A
Country	US
Kind code	B2
Filing date	Apr 15, 2015
Priority date	Aug 15, 2011
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

With a TFT using an oxide semiconductor film, there is such an issue that oxygen deficit is generated in a surface region of the oxide semiconductor film after performing plasma etching of a source/drain electrode, thereby increasing the off-current. Provided is a TFT which includes: a gate electrode on an insulating substrate; a gate insulating film on the gate electrode; an oxide semiconductor film containing indium on the gate insulating film; and a source/drain electrode on the oxide semiconductor film. Further, the peak position derived from an indium 3d orbital in the XPS spectrum of a surface layer in a part of the oxide semiconductor film where the source/drain electrode is not superimposed is shifted towards a high energy side than the peak position derived from the indium 3d orbital in the XPS spectrum of an oxide semiconductor region existing in a lower part of the surface layer.

First claim

What is claimed is:

1. A thin film device manufacturing method, comprising: forming a gate electrode on a substrate; forming a gate insulating film on the gate electrode; forming an oxide semiconductor film on the gate insulating film; depositing a source/drain electrode metal film on the oxide semiconductor film; and patterning the source/drain electrode metal film by using a plasma gas containing fluorine to form a source/drain electrode, wherein
the plasma gas containing the fluorine is generated by an inductive coupling plasma source, and the substrate is placed on an earth potential electrode to perform etching of the source/drain electrode metal film.

2. The thin film device manufacturing method as claimed in claim 1 , wherein
sulfur hexafluorine, tetrafluoromethane, argon, oxygen, or a mixed gas of those is used as a reaction gas of the inductive coupling plasma source.

3. The thin film device manufacturing method as claimed in claim 1 , further comprising:
placing the substrate on an earth potential electrode to perform etching of the source/drain electrode metal film while fluoridating a surface layer in a part of the oxide semiconductor film where the source/drain electrode is not superimposed; and
shifting a peak position derived from an indium 3d orbital of an XPS spectrum in the surface layer towards a high energy side than a peak position derived from an indium 3d orbital of an XPS spectrum in an oxide semiconductor region existing in a lower part of the surface layer.

Assignees

• Takechi Kazushige
• Iwamatsu Shinnosuke
• Kobayashi Seiya
• Watanabe Yoshiyuki
• Yahagi Toru
• Nlt Technologies Ltd

Inventors

• Takechi Kazushige
• Iwamatsu Shinnosuke
• Kobayashi Seiya
• Watanabe Yoshiyuki
• Yahagi Toru

Classifications

• H10D64/011

  of electrodes ohmically coupled to a semiconductor · CPC title

• H10P95/00 Primary

  Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass · CPC title

• H10D30/6757

  characterised by the structure of the channel, e.g. transverse or longitudinal shape or doping profile (TFTs having channel structures for preventing kink or snapback effects H10D30/6708; TFTs having lightly-doped source or drain extensions H10D30/6715) · CPC title

• H10D99/00

  Subject matter not provided for in other groups of this subclass · CPC title

• H10D64/01 Primary

  Manufacture or treatment · CPC title